Green azo dye.



UNITED STATES PATENT orr on.

JOHANNES JANSEN AND WILHELM NEELMEIER, 0F LEVERKUSEN, NEAR COLOGNE,

GERMANY, ASSIGNORS TO FARBENFABRIKEN VORM. FRIEDR. BAYER & (30., OF

ELBERFELD, GERMANY, A CORPORATION OF GERMANY;

GREEN AZO DYE.

No Drawing.

T 0 all whom it may concern:

Be it known that we, JOIIANXl-IS Jnxsnx and "lmnamr Nnnm nncn, doctors of philosophy, chemists, citizens of the German Empire, residing at Levcrkusen, near Cologne, Germany, have invented new and useful Improvements in Green Azo Dyes, of which the following is a specification.

- 'lheapresent invention relates to the manufacture and production of a new dyestufi' of great technical value. It is obtained by combining the diazo compound of (S-chloro- 4 nitro 2 aminophenol with 1.8 diaminonaphthalene--sulfonic acid and treating the thus obtained diaminoazo compound with ni trons acid. The resulting dyestufi' contains an azimido roup. When dyed direct it yields violet shades, which when subsequently treated with bichromates change into pure yellowish-green shades. The same dyestufi" can be obtained by combining the diazotized 6chlo1o-4-nitr0-2-aminophenol with LS-aZiininonaphthalene-sultonic acid.

In order to carry out the new process more fully the following example is given, the parts being by Weight :-18.8 parts of 6-chloro-i-nitro-2-aminophenol, made into afine paste with water and 140 parts of hydrochloric acid (19 Re.) are diazotized with 7 parts of sodium nitrite. The diazo compound thus obtained is then added to a neutral solution of the sodium salt of 24.8 parts of 1.S-naphthalene-diamin-esulfonic acid to which 35 parts of sodium acetate have been added. The combination is complete after 65-70 hours. The dyestuil separates during this time. It is filtered otl, dissolved in a sodium carbonate solution and to this solution after having been cooled to 0 C. 50

Specification of Letters Ratent.

Application filed February 26, 1910v Serial No. 546,041.

Patented June 14, 1910.

rendered alkaline with sodium carbonate and heated to 50 C. The new dye is then precipitated with common salt. It is, after being dried and pulverized, a black powder soluble in water with a violet color, soluble in concentrated sulfuric acid with a bluislr green color and yielding by reduction with stannous chlorid and hydrochloric acid 51%- diamino. finchlorophenol and 2 amino 1.8- aziminonaphthalenel-sulfonic acid. The same dye. results by" combining the diazo compound obtained from 18.8 parts of fi-chloro-d-nitrofi alninophenol with a solution of 25 parts of l.8-aziminonaphthalene-4- sultonic acid containing an excess of sodium carbonate.

We claim:

The herein-described new dyestuft, obtainable by combining the diazo compound of (S-chloro-el-nitro-2-aminophonol 1 with 1.8-diaminonaphthalene-i-sulfonic acid and treat.- ing the diaminoazo compoundlhus obtained with nitrous acid which new dye is,-after be 

